1. Field of the Invention
This invention is concerned with improvements in or relating to mixing apparatus.
2. Prior Art
In order to mix powder or liquid materials, for example polymer powders or rubber components in powder form, it is known to introduce the material into a mixing chamber of a mixing apparatus and rotate one or more rotors which are within the chamber so that the material is mixed thereby. An apparatus of this kind is described, for example, in U.S. Pat. No. 4,053,144, issued Nov. 11, 1977, and is assigned to the assignee of the present invention. In such mixing apparatus, the rotors comprise shaft portions which extend beyond the mixing chamber through an aperture in a wall of the chamber for connection with motors used to rotate the rotors. It is necessary to seal the aperture, between the rotor and the wall of the mixing chamber, as otherwise the powder or liquid material could escape from the mixing chamber.
It is one of the various objects of the present invention to provide a mixing apparatus having improved sealing means for sealing between the wall of the mixing chamber and the rotor.